2-keto-5-imino-4-(amino-formyl-imino)-imidazolidine aldehyde resins



2,700,032 PatentedJan. s, 1955 Z-KETO-S-INHNOA-(AMINO-FORMYIi-IMINO) IlVIlDAZOLIDlNE ALDEHYDE RESINS Thomas Boyd, Springfield, and Henry A. Walter, Longmeadow, Mass., assignors to Monsanto Chemical Company, St. Louis, Mo., a corporation of Delaware No Drawing. Application October 7, 1950, Serial No. 189,052

5 Claims. (Cl. 260-675) Another object is to provide 2-keto-5-imino-4(amino-\ formyl-imino)-imidazolidine-aldehyde reaction products.

Still another object is to provide ethers of aldehyde- 2 keto 5 imino 4(amino-formyl-imino)-imidazolidine reaction products.

These and other objects are attained by reacting 2- keto-S-imino-4(amino-formyl-imino)-imidazoline with aldehydes to form thermosetting resins which may be further modified by reaction with organic hydroxy compounds.

The following examples are given in illustration and are not intended as limitations on the scope of this invention. Where parts are mentioned, they are parts by weight.

Example I 2 keto 5 imino 4(amino-formyl-imino)-imidazolidine was prepared by the oxidation of uric acid using potassium ferricyanide as an oxidizing agent according to the method described by Denicke in Liebigs Annalen, vol. 349, pp. 286-287. The oxidation product was dissolved in sodium hydroxide, the solution was filtered to remove impurities and the 2 keto 5 imino 4(aminoformyl-imino)-imidazolidine was precipitated with sulfuric acid. The precipitate was recovered by filtration and thoroughly washed to yield a white, crystalline material soluble in alkalies and insoluble in acids. On analysis, the product was found to be substantially pure 2-keto-5- imino-4 amino-formyl-imino -imidazolidine.

2 keto 5 imino 4(amino-formyl-imino)-imidazolidine may be represented by the following formula:

One mol of 2-keto-5-imino-4(amino-formyl-imino)- imidazolidine and four mols of formaldehyde in the form of a 37% solution in water were mixed with suflicient sodium hydroxide to attain and maintain a pH of about 8 to 9. The solution was then refluxed for about one hour at atmospheric pressure to obtain a solution of tetramethylol 2 keto 5 imino 4(amino formyl imino)- imidazolidine. The water was then removed by vacuum distillation to yield a slightly yellow, solid, brittle resin. The resin was soluble in alcohols, ketones and other common solvents.

Example III the die used and that only infinitesimal shrinkage had occurred during the curing and cooling.

Example IV One mol of resin produced as shown in Example II was dissolved in six mols of methanol. 0.1 mol of formic acid in aqueous solution was added to the methanol solution which was then boiled under reflux at atmospheric pressure for about one hour to produce a methanol solution of the tetramethyl ether of tetramethylol 2-keto- 5-imino-4(amino-formyl-imino)-imidazolidine. The excess methanol was removed by vacuum distillation to yield a slightly yellow, clear, liquid resin. The resin was soluble in water and organic solvents.

The ether resin could be cured to a solid, insoluble, infusible state by heating it at from C. to C. with or without the aid of an acid curing catalyst. It was compatible with alkyd resins to produce a gloss coating composition having excellent weathering properties. It could be applied to textiles and cured thereon without the use of acid catalysts, to shrinkproof and creaseproof the fabrics and to greatly diminish chlorine pickup of the fabrics during subsequent bleaching operations.

2 keto 5 imino 4(amino formyl imino) imidazolidine may be reacted with other aldehydes than the formaldehyde shown in Example II or a mixture of aldehydes may be used. Among the useful aldehydes are formaldehyde, acetaldehyde, benzaldehyde, cinnamaldehyde, crotonaldehyde, acrolein, methacrolein, furfural, etc. The amount of aldehyde which will react with the acid may vary from less than one mol to 5 mols per mol of 2-keto-5-imino-4(amino-formyl-imino)-imidazolidine. An excess of aldehyde or aldehyde mixture beyond 5 mols may be used, the excess being removed after the reaction is complete. The pH of the reaction medium may vary between about 8 and 9, sodium or other alkali metal hydroxide or ammonium hydroxide, or a suitable buifer being used to maintain the desired pH.

The resins thus obtained are slightly colored, fusible and soluble in alcohols, ketones, etc. They may be cured to an insoluble, infusible state by heating them with or without acid curing catalysts such as ethyl sulfonic acid at a temperature from about 100 C. to about 200 C. An especially advantageous feature of the resins is the almost complete absence of shrinkage during the curing and cooling operations. This feature permits the preparation of molded articles within exceptionally close tolerances for precision molding uses.

The resins may be mixed before molding with other curable aminoplasts such as aldehyde condensation products of urea, thiourea, dicyandiamide, guanidines, aminotriazines, e. g., melamines, etc. to decrease the shrinkage of such aminoplasts during molding operations. Likewise, mixtures of the imidazolidine may be mixed with one or more of these compounds and the mixture condensed simultaneously with the aldehyde.

Conventional additives such as fillers, dyes, pigments, lubricants, etc. may be mixed with the new resins prior to the molding operations.

As typified in Example IV, the aldehyde condensation products of 2 keto 5 imino 4(amino-formyl-imino) imidazolidine may be further reacted with organic hydroxyl-containing bodies such as alcohols and phenols under acid conditions to provide ether resins for use in coating compositions alone or in combination with alkyd resins, and for use as textile or paper treating agents. Among the alcohols and phenols which may be used are methanol, ethanol, butanol, octanol, cetyl alcohol, stearyl alcohol, phenol, alkyl phenols, cresols, resorcinol, xylenols, allyl alcohol, crotyl alcohol, benzyl alcohol, cinnamyl alcohol, etc. A mixture of two or more alcohols may be used in which case an excess of the lower alcohol is preferably reacted first and then the higher alcohol or phenol is reacted to exchange alcohol groups.

The amount of alcohol or phenol used may vary according to the amount of aldehyde reacted with the 2- keto 5 imino 4(amino-formyl-imino)-imidazolidine or may be substantially less than that amount. The maximum amount of alcohol or phenol which can be made to react is 5 mols per mol of penta-alkylol derivative of 2- keto-5-imino-4 (amino -formyl-imino) -imidazolidine. excess of alcohol or phenol may be used.

According to another embodiment of this invention 2' keto-5-imino-4 amino-formyl-imino) -imidazo lidine may be reacted simultaneously with an aldehyde and an alcohol or phenol under acid conditions to produce ethers of the alkylol derivatives of 2-keto-5-imino-4(aminoformyl-irnino -irnidazolidine.

The ether resins obtained by either method are compatible with alkyd resins and are valuable for increasing the adhesion of alkyd resins to metal, glass, ceramics, etc. and in diminishing the tendency of the alkyd resins to shrink away from coated surfaces. They are also valuable for treating textiles to shrinkproof and creascproof the textiles, to diminish the chlorine pickup of the treated fabrics during subsequent bleaching operations, and to serve as a fixing-agent for dyestuflfs.

It is obvious that many variations may be made in the products and processes of this invention without departing from the spirit and scope thereof as defined in the appended claims.

What'is claimed is:

1. A thermosetting resin comprising the condensation product of Z-keto-S-imino-4(amino-formyl-imino)-imidazolidine and an aldehyde.

2. A thermosetting resin comprising the condensation product of 2-keto-5-im'ino-4(amino-formyl-imino)-im'idazolidine and formaldehyde? 3. A thermosetting resin comprising the condensation product of Z-keto-5-imin0-4.(amino-formyl-imino)-irnidazolidine, an aldehyde and a compound taken from the group consisting of alcohols and phenols.

4. A thermosetting resin comprising the condensation product of 1 mol of 2-keto-5-imino-4-(amino-formylimino')- imidazolidine and 4 mols of formaldehyde.

5. A .thermqsetting resin comprising the condensation product of 1 mol of 2-.k6I0-5-imino-4-(amino-iormylimino)-imidazolidine, 4 mols of formaldehyde and 6 mols of methanol.

References Cited ,in the file of this patent UNITED STATES PATENTS DAlelio Oct. 19, 1943 Walter July 4, 1950 OTHER REFERENCES 

1. A THERMOSETTING RESIN COMPRISING THE CONDENSATION PRODUCT OF 2-KETO-5-IMINO-4(AMINO-FROMYL-IMINO)-IMIDAZOLIDINE AND AN ALDEHYDE. 